In a small bowl, combine the warm milk and yeast. Let it sit for about 5 minutes until frothy.

In a large mixing bowl, whisk together the all-purpose flour, bread flour, sugar, and salt.

Make a well in the center and add the yeast mixture, softened butter, eggs, and vanilla extract. Mix until a dough forms.

Knead the dough on a floured surface for about 5-7 minutes until smooth and elastic.

Place the dough in a greased bowl, cover it with a clean kitchen towel, and let it rise in a warm place for about 1 hour or until doubled in size.

Preheat the oven to 375°F.

After the dough has risen, punch it down and turn it out onto a floured surface. Roll it into a rectangle about 1/2 inch thick.

Brush the melted butter over the surface of the dough.

Fold the dough into thirds like a letter, then roll it out again into a rectangle. Repeat this folding and rolling process two more times.

Cut the dough into 12 equal squares. Place each square into a greased muffin tin, tucking the corners in.

Let the dough rise again for about 30 minutes.

Bake in the preheated oven for 20-25 minutes or until golden brown. Remove from the oven and let cool slightly before serving.